Upgraded/larger PAS reservoir tank?

[Space Cadet]

My standard PAS tank appeared to be leaking following a day on track, didn't seam to be leaking from any cracks or a bad cap seal etc. I've since found out that the cap is a pressure-valve and that they're designed to let the pressure out through the valve in the centre of the cap and therefore potentially also some of the fluid if things get too hot. Apparently this is a 'normal' thing to happen and nothing to worry about but if I wanted a remedy then should fit a larger tank which would allow for more expansion and also the larger amount of fluid would also keep things a bit cooler.
Anyone else had this problem? Or fitted an 'upgraded' tank? Thanks!

 

[Chip-mk1]

Yes it can help, another option is to simply drill fit the cap big enough to put a metal fitting in and run into your catch tank

 

[Space Cadet]

Thanks Chip, I don’t have a catch-tank just have a small ITB breather filter. The fluid level in the PAS tank actually looks to be fine, obviously it was just getting hot on track, expanding and then forcing its way out through the pressure-cap. So apart from a bit of fluid leaking out now and again, this isn't a problem then? For the sake of a new larger tank are there you know of to-hand that accept the same size standard hoses?

 

[Chip-mk1]

I dont know of a direct fit I am afraid mate no, although someone like Pro-Alloy would certainly be able to knock you one up but then of course it would be expensive as a custom job.

Its perfectly normal for the clio to do this with its power steering fluid, was very common on the mk1 as well his is mechanically a pretty much identical setup (ie the pump is same internally etc)

The other option that you have is to put a small oil rad in line with the PAS pipe to cool the fluid.

 

[Space Cadet]

Thanks Chip, much appreciated. I'll perhaps think about fitting a catch-tank at some point then which I can also use for the PAS 'overflow'.

 

[BIGASH]

I have got a larger PAS tank with a takeoff to my catch tank and it seems to get just as hot and then overflows into the catch tank! Chip's idea is really good to be fair and you will be able to get the pneumatic fittings on ebay for a couple of quid

 

[Chip-mk1]

Keeping the PAS not quite topped up to max gets rid of a lot of the issue, many years ago when I first had this issue on my mk1 (where it spews down the wing due to the location of the tank) I started off by keep topping it up every session as I didnt want to risk running out of fluid, then when I forgot to take some spare fluid one trackday the level dropped as I did sessions, and as it got lower the amount coming out got a lot lot less as it meant there was obviously a lot more room for expansion now.
So I think running only just above the minimum is a good way to do it and thats what I now tend to do.

 

[Space Cadet]

Thanks James, possibly its always been doing this but I've only just recently noticed. And thanks Chip, I think the PAS fluid has recently been topped-up which would explain why I've only recently noticed it leaking out! I'll keep an eye on the level and not top it up and see how it goes.